There is a bulge in the left root of thigh, which is considered to be related to lipoma, enlarged lymph nodes and sebaceous cysts. 1. Lipoma: due to the distribution of adipose tissue in the root of thigh, heredity, obesity, trauma, etc. may lead to abnormal proliferation of adipose tissue causing the formation of lipoma, which is mostly manifested as a localized lump of varying sizes, with a soft texture, and can be moved when pushed. 2. Enlarged lymph nodes: for patients with pelvic inflammatory disease or malignant tumors such as rectal cancer, colon cancer, cervical cancer, etc., if the inflammation or cancer cells affect the lymph nodes in the groin, the small bumps with hard texture will be touched. 3. Sebaceous cyst: this disease is due to the sebaceous gland duct obstruction and lead to the sebaceous gland fluid stagnation in the local formation of retention cysts, and the local skin is closely adhered to the skin, touching the fluctuation of no feeling. For patients with a bulge on the left side of the thigh, it is recommended to improve the ultrasound and other related examinations to clarify the cause of the disease under the guidance of the doctor to actively treat.